Bone Abstracts

Background: Traditional treatment of X-linked Hypophosphatemic Rickets, while beneficial in minimizing disease associated deformity, is limited by development of treatment related complications, including nephrocalcinosis and hyperparathyroidism.

Presenting problem: A 10-year-old female with XLH rickets was seen for transfer of ongoing care. She had been treated since birth with Calcitriol and phosphate supplement at typical replacement dosing (18 ng/kg/day divided BID and 37 mg/kg/day divided QID, respectively). Initial laboratory investigations at time of first assessment revealed mild hyperparathyroidism and hypercalcemia.

Clinical management: Despite titration of phosphate and calcitriol dosing and eventual discontinuation of all medications, hyperparathyroidism persisted. Parathyroid adenoma was not identified by sestamibi scan or ultrasound. Subtotal parathyroidectomy of 3.5 glands was performed. Post-operatively the patient developed prolonged, severe hypocalcemia lasting 4-weeks consistent with co-existent hungry bone syndrome and hypoparathryoidism.

Discussion: Management of X-linked Hypophosphatemic rickets with conventional therapy is complicated by the potential for iatrogenic complications. We present an XLH patient with tertiary hyperparathyroidism and post-surgical hungry bone syndrome and hypoparathyroidism. Emerging therapies may offer improved outcomes in disease management and prevention of iatrogenic complications.

Disclosure: The authors declared no competing interests.